This invention relates to a process for correcting railway tracks.
Such a technique is known in which a survey of a track is made and pen chart recorder makes a recording of the track representing the condition of the track before alignment. A skilled operator then takes the recording and draws a "best line" through the recorded curve to average out the errors. The corrected record is then used in a track aligning apparatus which makes use of a photocell/potentiometer/shadow board technique for aligning the surveyed track.
In another known technique an optical record is obtained during survey of the track and this can be compared with a "standard" optical record, for example by simultaneous screening. Here again, a skilled operator is necessary to interpret the differences between the actual and the ideal curves.
Both of the above techniques have the disadvantage that the alignment information fed to the track aligning machine is not mathematically accurate but is dependent on the skill and experience of the operator.